The present invention relates to material handling and in particular to methods and apparatuses for conveying packages and a mechanism for controlling the location of packages on a conveyor.
Conventional conveyor systems convey large numbers of packages at high speed, especially in the parcel delivery industry wherein the packages are sorted according to the desired categories. The efficiency with which the packages are handled can be seriously diminished when a plurality of smaller packages, irregular sized or shaped items, or a mixture of large and small articles pass together on the conveyors as a single unit.
Problems occur with scanning and separating packages and parcels which travel through the conveying system as an aggregate unit rather than in a single file. Large packages hide small parcels and small side-by-side packages cause problems whenever they pass simultaneously through a bar code scanner causing confusion and sorting problems. Moreover, packages such as bags or other flexible containers having the weight distributed unevenly, or where the width and length of the container are extreme, or where the container is soft or only partially full such as a floppy partially filled bag of mail tend to present sorting problems in that they do not move in predictable lateral patterns.
The use of unscrambling conveyors sometimes referred to as singulators uses a plurality of driven rollers or belts whose axes extend obliquely relative to the direction of conveyance causing packages to be displaced laterally toward one side of the conveyor and become aligned behind one another.
Typical singulator conveyor systems for sorting parcels in typical applications comprise devices used that take randomly arranged items and convert the random flow to a single file stream of items. The items are conveyed forward with both forward and lateral forces and aligned along one side. A device can be placed after the aligned stream of items and items that did not make it all the way to the wall on the aligned side, are separated laterally away from the primary stream of parcels. Typical configurations direct the laterally removed items and recirculate them back to the skewed roller section for another pass and opportunity to be aligned against the wall, to be passed through with the primary line of flow. Items are conveyed forward with both forward and lateral forces and aligned along one side.
Present technology works well for rigid parcels, like a box, but items that do not behave as a rigid item like flexible parcels or large bags containing several small items are separated in accordance with their center of gravity and tend to be removed from the parallel stream even when the item is not abreast of another item.
Rearrangement of clusters of articles into a singulated single file is difficult to accomplish with packages having one dimension that is significantly greater than its other dimensions. If several packages having unequal loading, partially filled bags or boxes, or long and slender articles are conveyed side-by-side, conventional article singulation conveyors have difficulty separating side-by-side pairs into single file especially over a short distance and residence time. Packages having unequal weight, irregular dimensions, and off-set center of gravity can get repeatably shifted onto the output of the singulation conveyor. Occasionally instead of being positioned in single file, some of the packages may be conveyed abreast of one another, i.e., in side-by-side relationship traveling two abreast. The combined width of the two packages may present a problem at a downstream location in the conveyor system.
The need exists for a singulator conveying having separation capabilities effective in separating side-by-side articles including packages and parcels having unequal loading such as different sized packages (e.g., boxes, flats and softpacks), partially filled bags or boxes, or long and slender articles having an offset center of gravity into one or more rows of single file singulated articles over a short distance and residence time.
The present invention insures that two of more small items abreast of one another are separated while permitting large items to pass thorough the singulator even when the item is a large bag of small items.
Sorting parcels in typical applications devices take randomly arranged items and convert the random flow to a single file stream of items. Items are conveyed forward with both forward and lateral forces and aligned along one side. A device can be placed after the aligned stream of items and items that did not make it all the way to the wall on the aligned side, are separated laterally away from the primary stream of parcels. Typical configurations direct the laterally removed items and recirculate them back to the skewed roller section for another pass and opportunity to be aligned against the wall, to be passed through with the primary line of flow. Prior art conventional conveying systems work well for rigid parcels, like a box, but items that do not behave as a rigid item, like a large bag of small items tend to be removed from the parallel stream even when the item is not abreast of another item. The instant invention provides an apparatus and method capable of separating rigid parcels as well as large bags of small parcels.